1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to the selection of a Digital Subscriber Line (DSL) scheme from among all DSL schemes, profiles, and combinations, collectively referred to as xDSL; implementation of filtering and other signal enhancements of an xDSL signal; and universal demarcation physical interconnect of xDSL within all common Network Interface Devices (NIDs).
2. Description of the Related Art
A demarcation point, referred to as a network interface device (NID), is typically provided between a telephone subscriber's premises line and an incoming line from a telephone service provider, and is commonly mounted to a pole or outside wall of the subscriber's premises. However, a demarcation point may also be located, for example, at a wall plate of a distribution panel within a communications room on the ground floor of a Multi Dwelling Unit (MDU).
The NID enclosure can include a base section that is secured to a subscriber's premises, and to which a telephone subscriber line module is affixed. An interface device or module, typically mounted within an NID for physically connecting a telephone subscriber line with a telephone service provider line, is referred to as a “subscriber line module” or “subscriber bridge.” Telephone service provider lines enter the NID enclosure and are connected to the telephone line of a subscriber's premises via a subscriber line module.
With the advent of a digital subscriber line (DSL) and very high speed DSL (VDSL) services, the telephone subscriber may have multiple services, such as telephone, Internet, or cable television, supplied on a single line or cable from the telephone company. In these situations, the NID becomes more complex in that it must contain circuitry to separate the signals of different frequencies coming in from the telephone company on a single line into signals for the subscriber's telephone, television, and Internet signals.
A variety of related art interface modules are available to meet these needs. These modules are usually of a standard shape that “snap” into the NID enclosure. However, as the number of interface modules in an NID enclosure becomes larger, for example, when a larger number of connections are needed to provide multiple services, the wiring inside the NID can become unwieldy.
Likewise, the interface modules and NIDs are sold by many different manufacturers. Accordingly, these modules may have different physical footprints and may not be easily adaptable to interact with other modules or the NID. For example, interface modules and NIDs are available with AFL Keptel or “K” footprint, AFL Seicor or “S” footprint, Tyco “K” footprint, Tyco “S” footprint, Corning Cable Systems “S” footprint, and Corning Cable Systems “Universal” footprint. Each type requires an interconnect scheme and splitter module of different physical shape.
Also, many service providers have deployed three-line space NIDs and have populated these NIDs with two line modules or interface module which occupy two line spaces in order to provide telecommunications service. Related art interface modules require at least two line spaces, thereby reducing the number of line spaces available for additional services or for future expansion. However, related art technology does not provide the capability for expansion of features or customization as part of an interface module. For example, adding a balanced two (2) wire differential circuit conversion to an unbalanced coaxial single-ended circuit would require installing a completely new device. Related art modules are either a stand alone splitter-filter module or a combination splitter-filter-balun module. These modules are not field upgradeable and must be replaced at considerable expense both in parts and skilled labor if, for example, the profile filtering or output connectivity required adjustment, re-configuration or replacement. Another option is to replace the NID itself with a larger unit, which is also expensive and inefficient.
Related art interface modules do not provide a way to attach auxiliary modules within one line space, that may be required for the addition of associated hardware, mechanical network system customization, security features. For example, related art splitter modules do not provide an add-on means to use alternate connector types. Instead, several specific splitter modules have been developed that employ the coaxial “F” connector style.
In addition, related art splitter modules are not mechanically or electrically modular in nature. Therefore, they do not allow for field configuration of xDSL profile filtering, system enhancements, or interconnect variations, while taking up only a single line space in the NID.
The vast majority of related art splitter-filter modules employ screw terminals to make connections at the demarcation point, requiring special tools, extra labor by skilled technicians and occupying excess space within the NID.
xDSL splitter, filter and signal conditioning devices may also be located at the NID interconnect point. xDSL refers collectively to data transmission methods such as, ADSL, ADSL2, ADSL2+, VDSL, VDSL2 and SHDSL, as described in ITU-T G.993.2, G.992.1, G.992.3, G.992.5, G.993.1, and G.991.2, which are hereby incorporated by reference in their entirety.
xDSL profiles relate to specific frequency plans, power spectral density (PSD), modulation schemes, noise mitigation techniques, and data rates for transmission of data within a POTS system employing an unshielded twisted pair (UTP) wire, but are not limited to this transmission medium and are, on occasion, deployed using coaxial cable (COAX), multi-pair Ethernet cable or a combination of media.
Over the years a variety of NID enclosures have been fielded with each model having differing physical configurations and orientations. In response, a very large number of physically different xDSL devices have been created to fit within a specific NID model. Additionally, each device created for a specific model has several versions to support each xDSL profile, and each of these devices has associated enhancement modules. Thus, a large number of physically different xDSL devices are required to support the many NID installations currently deployed in the field.
With respect to splitter modules, related art splitter-filters are only matched to one xDSL profile, are constructed as a single fixed dual slot unit (i.e. consume 2 line spaces within an NID), and cannot accommodate reconfigurations or add-on enhancements. Thus, as the xDSL system develops or is modified to use an additional xDSL profile, the related art splitter modules must be physically replaced with a second module matched to the second xDSL profile. The need for multiple xDSL splitters, each matched to a specific xDSL profile as well as the NID significantly increases the cost of operating and maintaining an xDSL system.